I was running some dungeons for a 30's leveled locked toon and figured I would get him some of the DM equipment with the tokens when I noticed that I could no longer buy the charm slot items nor the shoulder armor.

Does anyone know why these choices are no longer available in the DM marketplace?

That happened a couple of days ago. I submitted a bug report on it. I've been buying some of those mysterious crates to see what I would get. Even though those charm and and armor items are no longer listed in the Market Place you can still get them from the mysterious crates.